FRANKFURT (Reuters) - Fresenius Medical Care (FMEG.DE: Quote, Profile, Research) will appeal against a U.S. court ruling that banned the German company from making, using or selling a key dialysis machine in the United States, FMC said on Monday.

"The company continues to believe with good reasons that these patents claims are invalid as determined by the U.S. Patent Office in recent reexaminations and will therefore appeal the court decision with confidence," FMC said in a statement.

"In addition, the company has prudently developed a back-up design while this legal process continues and expects no material impact on its product business with haemodialysis machines," the company added.

FMC shares were down 0.4 percent at 32.78 euros at 0720 GMT, compared with a 0.6 percent rise in the German blue-chip index .GDAXI.

Last week, lawyers at Bell, Boyd & Lloyd for Baxter International (BAX.N: Quote, Profile, Research) said FMC had lost the patent suit.

The order applies to FMC's 2008K haemodialysis machines and takes effect on Jan. 1, 2009. The judge also ordered FMC to pay royalties of 10 percent on each machine sold until then and 7 percent on all disposable products used with the machines.

FMC makes about half of all the dialysis machines sold in the world. It reported $6.6 billion in revenues in North America last year, more than two-thirds of its total sales.

It sells different haemodialysis machines in Europe, which were not part of the U.S. case, a spokesman for Bell, Boyd & Lloyd said on Saturday.

FMC sells its 2008 series dialysis machines as 2008H and 2008K models in North America and 4008 and 5008 series models in the rest of the world.